| 摘要 |
The invention provides a Virtual Local Area Network (VLAN) over a DLSw interconnection so that VLAN identification is preserved as a packet is forwarded from a source VLAN over the TCP/IP link of the DLSw interconnection to a corresponding destination VLAN. A packet assigned to a VLAN is received by a first router. The first router uses a universal parser to determine the VLAN assignment of the packet. The parser is universal as it responds to the type of packet and type of VLAN (Ethernet, IEEE 802.5, etc.). The parser then writes VLAN information into a data structure in the router memory. The parsed data written into the data structure may include the following: the VLAN identification; a user priority identification; a CFI tag field; etc. The information fields in the data structure are assigned to the particular packet as it is processed by the router. Finally, as an outgoing encapsulated packet is built by the router, the fields of the data structure are read by the processes building the packet and written into fields of the encapsulating header. An encapsulated packet is then built by the first router for transmission over a TCP/IP connection with an encapsulating SSP header. A second router receives the encapsulated packet. The second router then builds a VLAN packet in response to the VLAN identification read from the encapsulating header and transmits the packet onto a destination VLAN corresponding to the source VLAN.
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